This invention is concerned with a moulding mechanism for a glassware forming machine, for example a glassware forming machine of the individual section type.
In U.S. Pat. No. 4,710,202, there is described a system for cooling one or more moulds of a moulding mechanism of a glassware forming machine of the individual section type. The moulding mechanism comprises a mould defining a cavity in which molten glass can be moulded and defining a plurality of cooling passages for the passage of cooling air through the mould, each cooling passage having an entrance in a bottom surface of the mould and extending upwardly through the mould. The mould has two movable side portions and a bottom plate mounted on a supporting plate. The mould side portions are movable into engagement with one another and the bottom plate to define a mould cavity and are separatable to allow removal of moulded glass from the mould. The supporting plate forms an upper wall of a plenum chamber extending downwardly and arranged to supply air, introduced by blowing means into an entrance of the plenum chamber, to passages in the supporting plate at substantially the same pressure. The passages in the supporting plate communicate, when the mould side portions are in engagement with one another and the bottom plate, with the cooling passages in the mould so that cooling air passes through the cooling passages.
The supporting plate is adjustable heightwise to accommodate moulds of differing heights but remains stationary during the operation of the machine. However, in other types of moulding mechanism, the entire mould or the bottom plate is raised and lowered during the operation of the machine by a piston and cylinder assembly located beneath the mould (see, for example, the moulding mechanisms described in U.S. Pat. No. 3,914,120). The presence of the piston and cylinder assembly beneath the mould prevents the installation of a plenum chamber of the type described in U.S. Pat. No. 4,701,202.
It is an object of the present invention to provide a moulding mechanism of the type in which at least a portion of the mould is raised and lowered during operation of the mechanism with a cooling system having the advantages of that described in U.S. Pat. No. 4,701,202.